Improved life standard has called for more attention on quality, functionality, and appearance of buildings. On the other hand, energy issues have engaged governments to request better energy saving effects for buildings.
Mortar construction in the current technology has the following defects: first, the roof is heavily loaded; second, the construction period is long, and construction is costly and time-consuming; third, the life span is short; fourth, the roof is tainted by mortar and difficult to clean; and fifth, repair is costly and difficult in case of leakage due to inability to find the cause.
In the past 5 years, new techniques in the sloping roof construction have been tried but invariably limited to using batten tiles for primary tiles and mortar construction for ridge tiles, which is commonly called semi-dry construction. The construction method results in an inability of damp air under the roof to discharge via the ridge portion due to the ridge being packed solidly with cement mortar, and thus, causes the batten tiles to decay quickly within a short life time for the roof. Further, the mortar constructed ridge tiles taint the primary tiles, are apt to loose and fall off, and thus, result in the leakage and economic loss.